1. Field of the Invention
The present invention generally relates to a substrate having a built-in chip and external connection terminals on both sides, and a method for manufacturing the same, and more particularly relates to a substrate having a built-in semiconductor chip wherein a resin member has the semiconductor chip contained therein.
2. Description of the Related Art
In these years, the semiconductor chip is becoming denser to a large extent, thus the size of the semiconductor chip becomes smaller. As the size becomes smaller, a substrate wherein a semiconductor chip is embedded, in other words, a substrate having a built-in chip is proposed.
FIG. 1 is a diagram showing a conventional substrate having a built-in chip. As shown in FIG. 1, the substrate having a built-in chip is composed of a support board 11, the built-in semiconductor chip 13, a resin member 17, vias 18, wirings 19, external connection terminals 20, a solder resist 21, solder balls 22, and a resin layer 23. The built-in semiconductor chip 13 is composed of a main body 14 and electrode pads 15.
The support board 11 supports the structure (the semiconductor chip 13, resin member 17 and others) built on the surface 11a of the support board 11. The side of semiconductor main body 14 on which the electrode pads are not built is bonded to the surface 11a of the support board 11 with the adhesive 12. The resin member 17 is provided on the support board 11 so as to cover the semiconductor chip 13. Each of the vias 18 provided in the resin member 17 is connected to the corresponding electrode pad 15 and exposed from the surface 17a of the resin member 17. The wirings 19 formed on the surface 17a of the resin member 17 are respectively connected to the via 18 and external connection terminals 20.
The external connection terminals 20 provided for disposing the solder balls 22 are exposed from the solder resist 21. The solder resist 21 exposing the external connection terminals 20 is provided on the resin member 17 so as to cover the wirings 19. The solder resist 21 is provided for protecting the wiring 19 so as to prevent the solder ball 22 from contacting the wiring 19. The solder ball 22 is provided on the external connection terminal 20. The solder balls 22 are provided for connecting another substrate such as the substrate 25 having a built-in chip. The resin layer 23 is formed on the undersurface 11b of the support board 11. The resin layer 23 prevents the structure (the semiconductor chip 13, resin member 17 and others) supported by the support board 11 from being warped together with the support board 11 (See Patent Document 1, for example).
[Patent Document 1] Japanese Patent Application Laid-Open Disclosure No. 2001-217381
However, the conventional resin member 17 has a low elastic coefficient at a temperature around its glass transition temperature, and its thermal expansion coefficient is high at a temperature lower than the glass transition temperature. Thus, as described above, it is necessary to retain the support board 11 so as to support the structure (the semiconductor chip 13, the resin member 17 and others) on the support board 11 even after the substrate 10 having a built-in chip is manufactured. Moreover, it is necessary to provide the resin layer 23 on the undersurface 11b of the support board 11 so as to prevent the substrate 10 having a built-in chip from being warped due to the deformation of the resin member 17. Accordingly, it is difficult to reduce the thickness of the substrate 10 having a built-in chip, since it is necessary to provide the support board 11 and resin layer 23. Furthermore, the support board 11 and resin layer 23 are provided on one side of the resin member 17, and the external connection terminals can be connected to only the other side of the resin member 17 on which the support board 11 and resin layer 23 are not provided. It should be noted that “the glass transition temperature” is a temperature below which the elastic coefficient of resin plummets. At the glass transition temperature, the resin structure transitions from the glass state to the gummy state.